Re: [Phys-l] Deceleration or Negative Acceleration

[Steve Highland <shighlan@uslink.net>]

> I instituted the use of "Reading Questions" in my classes this year, and I
> am getting some of the most interesting questions this semester from my
> students.
>
> This is one that I've not run into before...  A student has asked which is
> proper terminology:  "Negative Acceleration" or "Deceleration".
>
> Of the textbooks on my shelf, about half are for the first and the other
> half seem to use both interchangeably.  Interestingly, those that say
> "Negative Acceleration" is the proper term are all of a more recent
> vintage.
>
> Is one or the other really more used/acceptable?
>
> Thanks,
> Peter

To me, 'deceleration' means slowing down.  I don't see anything confusing
about that.  I think that's what the students think it means, too.

But "negative acceleration" can be either slowing down or speeding up,
depending upon how your +/- directions are chosen.  Now that IS confusing!

Anything that helps students discover this confusion so they can begin to
sort it out is good.

I'm glad you've found out what "reading memos' can do -- they're great!

Steve Highland